Greenhouse Gas Emission from the Danish Broiler Production ...

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Graphic illustration showing the contribution of the global warming potential (GWP) when producing 1 Danish broiler. Hatch egg production. 0,52 kg CO2‐eq.
Greenhouse Gas Emission from the Danish Broiler Production estimated via LCA Methodology 2011

Greenhouse Gas Emission from the Danish Broiler Production estimated via LCA Methodology. 2011 | 1

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Greenhouse Gas Emission from the Danish Broiler Production estimated via LCA Methodology Published August 2011 Autors Nicolaj Ingemann Nielsen1, Malene Jørgensen2* & Simon Bahrndorff3 1

AgroTech A/S, Institute for Agri Technology and Food Innovation, Agro Food Park 15, 8200 Aarhus N, Denmark.

2

Knowledge Centre for Agriculture, Poultry, Agro Food Park 15, 8200 Aarhus N, Denmark.

3

National Veterinary Institute, Technical University of Denmark, Hangøvej 2, 8200 Aarhus N, Denmark.

*

Corresponding author: contact details; e-mail: [email protected], telephone +45 8740 5370, mobile: +45 2171 7729 Funding: This report is part of the project “Climate friendly poultry production” funded by “Innovation subsidies” (The Danish Food Industry Agency), "Poultry levy fund" and “Organic levy fund”.

This report is made for the Knowledge Centre for Agriculture, Poultry and can be used for marketing purposes since it is produced in line with ISO14040 & ISO14044 standard. AgroTech cannot be held responsible for any errors concerning data received by the Knowledge Centre for Agriculture, Poultry.

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Content Abstract ....................................................................................................................................................4  Aim & focus ....................................................................................................................................4  Methods..........................................................................................................................................4  Results ...........................................................................................................................................4  Conclusions ....................................................................................................................................4  Background of LCA ..................................................................................................................................5  Goal and scope ........................................................................................................................................6  Focus..............................................................................................................................................6  Functional Unit ...............................................................................................................................6  Data ................................................................................................................................................6  Methods..........................................................................................................................................6  Process description ........................................................................................................................7  Life cycle inventory ...................................................................................................................................9  Rearing unit, the hatch egg production and hatchery ....................................................................9  Broiler production .........................................................................................................................10  Slaughterhouses ..........................................................................................................................11  Feed .............................................................................................................................................12  Energy resources .........................................................................................................................14  Other inputs ..................................................................................................................................15  By product: manure ......................................................................................................................15  By product: poultry waste .............................................................................................................17  Life cycle impact assessment and interpretation ...................................................................................20  Contributors to Global Warming Potential ....................................................................................20  Alternative Model Scenarios ........................................................................................................22  Comparisons to other investigations ............................................................................................23  Conclusion....................................................................................................................................24  References .............................................................................................................................................25 

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Abstract Aim & focus The aim of this study was to quantify the global warming potential (GWP) of chicken meat produced at Danish farms. Furthermore, the aim was to identify the hot spots of the products/processes that contribute substantially to the GWP of chicken. The functional unit was 1 kg of chicken defined as carcass weight for human consumption, i.e. meat, bones, liver, heart, kidneys, feet and neck were included while feathers, head, blood and intestines were excluded. The study includes GWP from the following rearing units, the hatch egg production, the hatchery, the broiler production, the slaughterhouse and all internal and external transports. No further GWP after the slaughterhouse was included in this study. Methods The GWP estimates in this study were based on a consequential approach using system expansion. The main by-products were manure and slaughter waste (feathers, head, blood and intestines) and, therefore, the system was expanded to include the avoided production of artificial fertilizer (ammonium nitrate) and mink feed (fish meal and maize), respectively. The GWP was calculated according to the Intergovernmental Panel on Climate Change (IPCC) 2007, using a 100 year time span (IPCC, 2007). Capital goods (e.g. buildings, machinery, roads, maintenance etc.) are only included in the basic data taken from existing data sources such as Ecoinvent (Ecoinvent, 2007). Production infrastructure at the farms and slaughterhouses such as buildings, machinery etc. was not included. Results The average live weight of a chicken was 2.127 g and the corresponding carcass weight was 1.489 plus 181 g of by-products (heart, liver, feet, neck), which is also used for human consumption. The GWP of one broiler packed at the slaughterhouse and ready for shipment was estimated to 3.85 kg CO2 eq. per broiler corresponding to 2.31 kg CO2 eq. per kg carcass weight due to the carcass weight of 1.670 kg. The contributor to the GWP of chicken meat was: hatch egg production, incl. rearing unit and hatchery (13.5%), broiler production (76.4%) and slaughtering (10.1%). At broiler farm level the major contributor to GWP was feed (91%). The variation between broiler farms was quite large ranging from 2.31 to 3.30 kg CO2 eq. per produced broiler. Conclusions The large variation in feed efficiency observed between Danish broiler producers despite virtually same level of feed quality available across houses and farms emphasize that the largest potential for reducing GWP here and now is to focus on intensified management and daily working routines in order to improve both weight gain and feed efficiency at the individual broiler producer in order to reduce GWP input in broiler production. The GWP of Danish chicken meat is within the same level as found in other LCA studies.

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Background of LCA A Life Cycle Assessment (LCA) is the assessment of environmental effects that a product or a service has during its lifetime, in principle from cradle to grave. In some cases, however, only a part of the life cycle is included in the assessment. System boundaries are included because the destiny of a given product is not always known when the product is sold, or the product is used as a part of other products. A strength of the LCA approach is that processes in the creation of a product/ service, that have the highest environmental impacts, can be identified. Thereby, the LCA may help the producers to make decisions concerning where to take actions in order to reduce the environmental impact, for example by optimising energy consuming processes. A LCA can contain a number of environmental impact categories, e.g. global warming, acidification, eutrophication, land use and photochemical smog. The different impact categories can be normalized to a single score, either monetary units or Quality Adjusted Life Years (QALYs). In this report only the global warming potential (GWP) is covered and no single score calculation is therefore necessary.

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Goal and scope Focus The current analysis and report follows the ISO 14044 guidelines (ISO, 2006). The aims of this study were thus to (1) quantify the global warming potential (GWP) of Danish broilers and (2) to identify products/processes with a major contribution to GWP of Danish broilers. The focus of the report was to identify sources of global warming potential of Danish broilers; other environmental impacts were not covered in this report. The results of this study were for use within a project called “Climate friendly poultry production”. The partners in the project include representatives from the hatch egg industry, a feedstuff company, a ventilation company, the broiler producers and two slaughter companies. The purpose of the project was to gain knowledge about the GWP of Danish broiler production. The results were not to be used as a comparative assertion (ISO, 2006). This report has been critically reviewed by an external LCA-expert (see appendix). Functional Unit The functional unit in this report was 1 kg of chicken meat defined as carcass weight, i.e. bones, liver and heart were included but feathers, head, blood and intestines were not included. The broilers were foiled and packed and thereby ready for transport to supermarkets, i.e. no further GWP after the slaughterhouse was included in this study. The inventory was related to a whole broiler but a given resource/input could be converted to the functional unit by dividing with 1.670 kg which is the average carcass weight of a broiler. Data Data from two rearing units, two hatch egg producers, one hatchery, six broiler producers and two poultry slaughterhouses were supplied by Knowledge Centre for Agriculture, Poultry (Bahrndorff and Jørgensen, pers. com.). These data were collected for the production year 2009. Otherwise data were used from different sources such as the Ecoinvent database, literature sources and personal communications with key persons. Methods TOOLS The calculations were made using the PC tool SimaPro 7.1 (PRé Consultants, 2008) together with LCA databases (Ecoinvent and LCA Food DK) that contain data for specific processes. LCIA The chosen life cycle impact assessment method (LCIA) is a single issue method called: “IPCC 2007 GWP 100A”. It only takes the global warming potential into account and is calculated according to IPCC 2007, using a 100 year time span. Using IPCC 2007, 1 g N2O and 1 g CH4 correspond to 298 and 25 g CO2, respectively. As a default the Ecoinvent database includes biogenic CO2 (carbon incorporated into plants/trees from the atmosphere). However, because the process of human consumption of chicken meat is not included, the LCA reported here excluded biogenic CO2 sources. Furthermore, GWP that arises due to land transformation was not included in this study due to lack of common methodology. This means that e.g. GWP arising from transformation of forest to fields for soybean production was not included and, therefore, GWP for soybean meal is underestimated (Dalgaard et al., 2008; Olesen, pers. com.).

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Capital goods (e.g. machinery, roads, maintenance etc.) were included in the basic data in the Ecoinvent database (Ecoinvent, 2007). However, buildings at the production facilities (farmhouses, slaughterhouses, etc.) were not included, because they were expected to be of minor importance. APPROACH The LCA reported here was based on a consequential approach (CLCA). In many processes more than one product was produced (joint production). In such cases it was necessary to divide the environmental impact from the process between the products (the main product and by-products). This was done by system expansion, where the impacts of the by-products were included in the assessment, rather than splitting the impacts due to e.g. weight or value of the different products (Kørnøv et al., 2007; Thomassen et al., 2008). CLCA implied marginal data for a given product and a marginal supplier was characterised as being able to increase its production at an economic favourable price. Thus CLCA had two important features: 1) it tried to model the processes that were influenced by a change in demand, 2) allocation of byproducts was avoided by system expansion. Although the LCA reported here was based on CLCA, a few standard processes from Ecoinvent were based on an allocation approach, such as palm oil. However, the significance of this process was limited, i.e.